To start off.......86 Sports Coupe, 4 cyl, Manual.
Well I'll try to explain it the best I can. So over the course of maybe the past week my car's problem has slowly gotten worse to what it is right now. The thing that makes this problem really weird is that there are a lot of "sometimes" in it. Sometimes I can start up my car and the idle will be perfectely normal and nothing else will really seem much wrong with it. Other times my car will hesitate on idle a little bit and sometimes even stall (when engine is cold OR hot). Sometimes when it stalls it will start right up and sometimes it won't start for 10 minutes. (hot or cold....again) Here's another weird part. It seems that my car will buck.....and that's it. It used to buck, once a day, but now it bucks probably every 1-2 minutes at least once, if not multiple times in a row. It will buck 3-4 times in a row at times and I know that's not a very good thing. I've noticed that it does it more often (not always....another "sometimes") when it is coasting at a fairly constant rate.
Here's what I've done with it to try and resolve it. I put a basically brand spankin new fuel filter in, I switched the IAC and MAP sensors, and the problems didn't get better, or worse. So I figured it was something else. On the car I have new spark plugs, fairly new (4000 miles maybe) spark wires, New ignition coil, fairly new rotor, fairly new PCV valve, fairly new air filter, and new ignition module. The catch with the ignition module is that the white grease (name slips my mind) that you put on the module and dist. shaft, the grease was only on the dist. side and not the module side (long story, just trust me). It has held up for probably about 1 1/2-2 months like that.
So what do you think the problem could be? I do know that I need to get a new cat. conv. because I believe that's where my exhaust leak is coming from and my emissions keep getting worse and worse. Plus I might need a new muffler. Besides all the new parts what's the first thing that would come to mind anyway? Because I could have bad new parts. I was thinking module maybe but then the car would start first time when the engine was hot, and didn't seem like it. I'm curious as to know if this could be bad plug wires? I ask that because after all it multiply bucked one time and then I ran like crap all of a sudden right after that. I finally got home and it turned out my #1 plug wire was on the exhaust manifold and frying. It got there because when I "broke down" 5 minutes on the side of the road, I was fidgetting around and I must have it the wire so it went on the manifold. Also just for FYI, this problem has happened before, but if I remember right, it just went away all on its own. Please help me if you can assist at all. This is my daily driver and I'll have precious few minutes tomorrow morning to see what I can look at.
Austin
------------------ Practice makes perfect, but since nobody's perfect, why practice? If life gives you lemons, take them and throw them at people you hate.
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12:17 AM
PFF
System Bot
Oreif Member
Posts: 16460 From: Schaumburg, IL Registered: Jan 2000
Check fuel pressure, The Fuel pump could be on it's way out. Check the spray pattern of the injector. If it's not a cone shaped pattern or it is dripping, it could be a dirty injector. (The low fuel pressure could also make the spray pattern look bad) With the car off and cool, take a hammer and tap the catalytic converter. If it sounds like a baseball is loose inside, It could be the cat clogging up. It sounds like you've proven it's not ignition related. I would check the fuel pressure first then if all good check the cat.
------------------ Happiness isn't around the corner... Happiness IS the corner.
[This message has been edited by Oreif (edited 03-11-2004).]
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12:52 AM
Jdlog Member
Posts: 494 From: Coral Springs, FL Registered: Jun 2003
Hi Austin. Seems like we all did a batch of suggestions about this car a few weeks ago. You may have covered most of them. A quick take on the situation leads me to ask: - Have you checked the fuel pump pressure for a regular flow? - Could some of the bucking you describe be a slipping clutch?...probably not but can't be discounted. - Can you check for obstructions in the exhaust? Some of these symptoms could stem from these except you didn't mention how the car behaves at WOT.
I would normally go for the ignition system first but you have it covered. Still, the new modules can act up. And they don't do this so much based on engine temp. as they do based on internal heat (higher when running). BTW, the paste is part of the heat-sinking process. It couples the back of the module to the distributor. If this is placed wrong or missing, bye bye moddie!
The distributor is not totally exonerated but let's give it the benefit of the doubt.
Anyway, fuel supply has to be my main suspect. See if you can think of any other symptoms.
Beno
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01:04 AM
ImmortalFirefly Member
Posts: 302 From: Northern Utah County, Utah Registered: Apr 2003
- Have you checked the fuel pump pressure for a regular flow? - Could some of the bucking you describe be a slipping clutch?...probably not but can't be discounted. - Can you check for obstructions in the exhaust? Some of these symptoms could stem from these except you didn't mention how the car behaves at WOT.
Beno
Hey thanks for the replies guys. This is probably a stupid question but what is WOT?.....anyway, a few other symptoms about this car. Ever since I've bottom it, the exhaust manifold does get a touch red in the dark. Sometimes its worse than others. I know in the past, it has heated up dramatically and totally screwed up different things in my car ( http://immortalfirefly.home.comcast.net/fiero.html ) (and don't mind the sayings in it, its just for picture purpose) On this exhaust note....maybe oh back in Dec. my car had a streak where it would, suddenly stop accelerating for a moment and then kick back in, but then it was followed by a BANG out the tailpipe with a small plume of smoke. So something in my exhaust isn't happy. Oh yeah! I just remembered this. This part was the really really weird thing about this whole ordeal. So right before my car bucked multiple times and then ran bad because of the bad spark wire (described above), it just stopped accelerating altogether. I couldn't accelerate for maybe.....5 seconds or so, and then it bucked wildly a few times and I could finally go again, but during this time my car didn't shut off, or try to shut off. It seemed fine like it was in idle or something. Now that I think about it, that clutch idea comes to mind.....sadly. One other noteable symptom about my car was that when I would sit in idle at an intersection for instance, if I sat there for maybe.......10 seconds, my SES light would come on. No real noticable changes in the engine performance or anything, but then "sometimes" it would go away after 6-7 seconds, but other times I would start driving and then it would go away. So I pulled my codes and I believe if I remember right, I get a 34 and 35.....I can't remember but they were the IAC and the MAP sensor. So when I changed the ones from my 84 over to the 86, everything seemed ok...but then the problem came back like it had the old stuff in it (yes I did clean the IAC as best I possibly could with Throttle body cleaner). Umm.........I doubt this but I'll throw it in anyway. My last oil change had 5w-30 oil in it, and because my car leaks oil like a mad mother, I had to put 1 quart of (same brand...Mobil1) 10w-30 oil, followed again by another one. Difference viscocity.....eh I don't know. Again please help me if you can guys. I know this is long but any help is greatly greatly appreciated.
Austin
------------------ Practice makes perfect, but since nobody's perfect, why practice? If life gives you lemons, take them and throw them at people you hate.
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01:42 AM
lurker Member
Posts: 12351 From: salisbury nc usa Registered: Feb 2002
WOT = Wide Open Throttle. for what it's worth i just today replaced a "nearly new" TPS with a new one, code 22 all gone (so far, knock on wood). i'd flush the computer memory and check for new codes. ------------------ '84 2m4 se, a work in progress http://www.mtsu.edu/~mkr2c/fiero.htm
[This message has been edited by lurker (edited 03-11-2004).]
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02:11 AM
Jdlog Member
Posts: 494 From: Coral Springs, FL Registered: Jun 2003
Well, as I read everything again I couldn't help fearing that one of a few "not new" replaced parts may be part of the problem. For example, what do you mean by a "basically brand spankin new fuel filter". If it was used in another car, however briefly, you'd be surprised what can happen to one used with a dirty tank in just days. BTW, are ALL the ignition wires new and in good shape?...I am thinking more of the coil-distributor wire.
However, I am now leaning more towards the exhaust...probably because I am exhausted and not necessarily thinking straight at 3:30AM . The progressive nature of the problem would support that the cat may be plugging. Do the tapping routine suggested by Oreif. I think you'll hear the loose stuff. Since this is a replacement that is coming fast anyway, it should be less of a pain to fix it now, I hope. I'll check later today to see how much fun you're having. Good luck!
Beno
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03:50 AM
ImmortalFirefly Member
Posts: 302 From: Northern Utah County, Utah Registered: Apr 2003
Well I'm about to go out and check a few things on the car. I'm gonna take the TPS outta my 84 and put it in the 86 and see if that improves anything at all. I'm gonna replace the wire that's damaged and check the cat. Other than that, that's about all I can do. With the fuel filter, I put it in the 84, and the 84 never actually started (I was thinking clogged filter), so the filter got gas, in it, it just didn't get anything else in it afterwards. How would I check for WOT (now that I know what it is)? Do I just start it up and letter rip up to like 3500-4000 RPM's or something?
That's all I can think of for now. Thanks guys. +'s around
Austin
EDIT: I remembered what I forgot. The problem that you were talking about a few weeks ago was on the 84 and me trying to get that monster started, but still to this day, it hasn't started on its own and I'm at a complete and utter loss about it. I'm parting it out if anybody is interested.
------------------ Practice makes perfect, but since nobody's perfect, why practice? If life gives you lemons, take them and throw them at people you hate.
[This message has been edited by ImmortalFirefly (edited 03-11-2004).]
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10:06 AM
ImmortalFirefly Member
Posts: 302 From: Northern Utah County, Utah Registered: Apr 2003
Well I switched the TPS and replaced that plug wire and now it runs ok....but it could be one of those "sometimes" symptoms. I pulled codes because I got that forbidden SES light again, and I got code 24......VSS....whatever. My car confuses me. I got that code right after I stopped driving and let it idle and as it idled down to whatever is normal (my tach is bad) and the light came on. I let it idle for some time and the light never went away. With the cat, I never jacked up the car, but I got a hammer, reached under, and banged it and it just banged....there was no reaction sound. So I could have a hollow cat and my problem could lie in the muffler (where most of my cat parts probably are ) One thing I did pick up on is that there is the slight sound of exhaust puffing out every 1/4 second or so, and then a bigger puff will come out once every 5 seconds give or take. Its near the exhaust manifold, but that's probably due to the fact that I'm missing 2 of the 7 bolts (I think there's 7). So that seems to be what's going on as of right now. I have realized 3 more things worth noting.
1. I had to cut the injector wires just below the TBI, and then reattach it. The way I have had to reattach is is by get another 18 guage wire and simply twisting the two wires together and putting electrical tape over them.
2. I did a small what I thought would be a WOT test and when I was at idle and I cranked up the RPM's and held them there for maybe 10 seconds. What I noticed was that maybe every 3 seconds or so, it would skip, just once, and continue going smooth.
3. I know I wanted to say something here but I already forgot.......*sigh*
Well that's what is going on as of right now. Maybe maybe I can get a pressure gauge later tonight to be able to check the fuel pressure after work. So as of right now, I'm classifying my car as not improved, cause problems could still be going on. On the note of the plug wire, I did notice 2 burnt areas on it. The one I created, and another one not too far way from it. I could see why that would make me skip but A) I can't see why that would make my car stall and B) It didn't seem too awfully "crispy", but did seem to break through the outter covering.
Austin
------------------ Practice makes perfect, but since nobody's perfect, why practice? If life gives you lemons, take them and throw them at people you hate.
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12:01 PM
Mike Smith Member
Posts: 172 From: MPLS, MN, USA Registered: Sep 2002
1. I had to cut the injector wires just below the TBI, and then reattach it. The way I have had to reattach is is by get another 18 guage wire and simply twisting the two wires together and putting electrical tape over them.
This is NOT the way to do it. I would suggest soldering the wires together or at the very least crimp them. Just twisting them could allow corrosion and with the temp differences (cold weather, hot engine, etc) the twist could loosen itself and cause intermittent connections.
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02:15 PM
eatoninside Member
Posts: 719 From: Tremonton, UT Registered: Aug 2003
I had a 'bucking' problem like the one you described. I was getting a code 33 or 34 (map sensor). It turns out it wasn't the actual MAP sensor itself, but it was the connector at the MAP sensor. I had to zip tie it on really tight to get it to connect right. Don't know if you are getting code 33 or 34, but I thought I'd chime in. Just my $0.02
My 84 would idle all day long but when going down the road, as soon as I got on the throttle it would buck to beat the band, and I would occasionally get a check engine light. I chased around to try to find the problem, IAC, MAP, TPS, etc. Turns out it was a leaking exhaust manifold and an apparently bad O2 sensor. Fixed leak and sensor and haven't had a problem since. You might want to check those.
Start w/ all your grounds, bad grounds & funky wiring create all kinds of chameleon symptoms, if all your connections are perfect then start checking sensor values. I think an 'Auto X-ray' is as invaluable as the 'Helms'! Advantage? Real time monitoring (w/ a passenger who knows how to read it) of most sensors while driving. Expense? Yeah, not cheap, manual + X-ray $350.+! Shop-time in my neck 'o' the woods is around $60. an hour X 6hrs.=$360. These two tools have more than paid for themselves, both in cash and in helping raise my understanding of how all those things interact. http://www.midwayautosupply.com/detailedproductdescription.asp?9197
[This message has been edited by gt88norm (edited 03-13-2004).]
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02:16 PM
Mar 14th, 2004
ImmortalFirefly Member
Posts: 302 From: Northern Utah County, Utah Registered: Apr 2003
Well here's how the car stands as of right now. Orief, with the wire, yeah I know its a horrible idea, but I have no other option. I have soldered those wires 3 times now......and they still break, bust come loose, whatever, and then they cause my car to buck and do very funny things. With the EGR valve, its working awesome. Its old, but its in great shape, As for the codes....umm........they've gone away *shrugs*. I haven't gotten one yet by sitting at idle. I got code 24 once, and I haven't gotten it since. As for the bucking.....well its ceased except for once....and that's the only time its done it. As for the coil, its about....1 1/2 months new. Now its time for my theory.
Remember that spark wire that was kinda getting hot in one spot? Well....here's my theory about it. Once, I died on the road and couldn't get her started up. So I took off the air filter and checked things out, went back in the car started it, and it started promptly. So what I did was let it idle for.....man it must have been 5 minutes, and it didn't have a single problem whatsoever. Now mind you, the air filter assembly is lying over the rocker arm cover while the car is still running. So after I think that everything is ok, I go to try and grab the assembly, and just as I move it, the instant second I do, the car stalls and shuts off. So I'm thinking.....that somehow and miraculously maybe that wire or some other wire near the back maybe? was causing the car to shut off for no reason. When I put everything back on and then it started up, I drop home but it still had that bucking problem, and on the way back home that night, (when it bucked repeatedly very hard and then I couldn't accelerate for a few seconds), then the wire got burnt by the manifold.
That's my theory and by no means do I have any idea of what I'm talking about ( ) since I'm only a novice mechanic, but can anybody else fill me in on if you agree with the theory or not?
Austin
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05:09 PM
Mar 16th, 2004
ImmortalFirefly Member
Posts: 302 From: Northern Utah County, Utah Registered: Apr 2003
I thought I would reply to this anyway although it doesn't seem like anybodies reading it anymore..........over the past two days the same problems have come back. I've since bought a new positive battery cable and bought new exhaust manifold bolts (all 7 instead of the 4 that were left) and it just seems like the problem is coming back as usual. I'm going to buy myself new plug wires since that seems to be the only route that I can take right now. I'm going to also put on a new negative battery cable and......see what that does. I can't really do much of anything else until I get some input. I'll check fuel pressure but then that leaves me at square one......*sigh*
Austin
------------------ Practice makes perfect, but since nobody's perfect, why practice? If life gives you lemons, take them and throw them at people you hate.
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12:47 AM
rogergarrison Member
Posts: 49601 From: A Western Caribbean Island/ Columbus, Ohio Registered: Apr 99
Good idea, bad plug wires cause all kinds of problems. You can test them by looking at them while its running in the dark. If you see sparks on them, throw them away.
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09:00 AM
Mar 20th, 2004
ImmortalFirefly Member
Posts: 302 From: Northern Utah County, Utah Registered: Apr 2003
A little update, I did manage to get a new pickup coil in the dist. and it did seem to help a little bit......but the problems are still there. I still need to get new wires, but that still doesn't make sense that my car would stall out like it does. At work today I couldn't get the stinkin car started, and my friend looked at it for a bit, and I had spark, and I had fuel, but air didn't seem like the problem either. So I took off the air cleaner cover and after a few starts, or whatever he messed with cause I couldn't see it, it started right up. He then adjusted my throttle cable so that it idles higher than what it normally does. He said something to the effect that it couldn't get enough air, or something, so gas would build up and then it would build up enough and just dump it all and flood it, so it killed my car. Any suggestions on that one? Thanks for your help guys. Muchly appreciated.
Austin
------------------ Practice makes perfect, but since nobody's perfect, why practice? If life gives you lemons, take them and throw them at people you hate.
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08:56 PM
Mar 21st, 2004
Whuffo Member
Posts: 3000 From: San Jose, CA Registered: Jul 2003
Ignition module. Remove, clean back of module and distributor baseplate. Use some solvent; clean all the old grease from the area where the module contacts the baseplate. Now feel the baseplate and back of the module - they should be smooth. It's absolutely critical that the module be in intimate contact with the baseplate. Now, reapply the heat transfer grease - if you need some, Radio Shack has it. Put it back together, tightening the bolts snugly and evenly.
There's a good chance that this will cure your problem.
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01:57 AM
PFF
System Bot
Dennis LaGrua Member
Posts: 15145 From: Hillsborough, NJ U.S.A. Registered: May 2000
Just goes to show that Fieros have gremlins. All kidding aside, there is no substitute for doing a total scan of the ECM and check of fuel pressure output as Orief has suggested. . A scan will give you information about the fueling, timing and output of all of the sensors throughout the RPM range. If you don't want to spend the bucks for a scan tool, you can scan with a program called WINALDL , a laptop (if you own one) and an inexpensive adapter cable. Interpreting the sensor and ECM data is not hard as sensor values are well documented
The progressive nature of the problem would support that the cat may be plugging. Do the tapping routine suggested by Oreif. I think you'll hear the loose stuff. Since this is a replacement that is coming fast anyway, it should be less of a pain to fix it now, I hope. I'll check later today to see how much fun you're having. Good luck!
) One thing I did pick up on is that there is the slight sound of exhaust puffing out every 1/4 second or so, and then a bigger puff will come out once every 5 seconds give or take. Its near the exhaust manifold, but that's probably due to the fact that I'm missing 2 of the 7 bolts (I think there's 7). So that seems to be what's going on as of right now. I have realized 3 more things worth noting. 
